(02-05-2018, 12:14 PM)Ulvetanna_imp Wrote:

(02-05-2018, 10:58 AM)SportsterDoc_imp Wrote:

(02-05-2018, 05:58 AM)Nortoon_imp Wrote: Honda Canada has just posted the specs for the 2018 CB1100 RS.
They state the fuel tank holds 16.8 liters.

I doubt Honda has made a different tank just for the Canadian 2017 CB1100 EX.
So I am going to assume the tank on my 2017 CB1100 EX holds 16.8 liters .... until I run out of gas on some lonely back road.

The real question is not what the tank will hold, filled up from dry, but what is usable capacity, before the fuel pump intake sucks air.

A carbed bke could be run dry.

Not so with EFI.

Be good to figure that the last 1/2 gallon or 2 liters may not be usable.

Fortunately the pickup tube is towards the rear of the tank, so there is more usable going uphill, versus downhill.

The real question is not what the tank will hold, filled up from dry, but what is usable capacity, before the fuel pump intake sucks air.

A carbed bke could be run dry.

Not so with EFI.

Be good to figure that the last 1/2 gallon or 2 liters may not be usable.

Fortunately the pickup tube is towards the rear of the tank, so there is more usable going uphill, versus downhill. I ran my 2015 ZX-10R dry and had to push it to a gas station.

Fired instantly after I gassed up.

So I believe the notion that a fuel-injected engine cannot/should not be run dry is, or has, become archaic. It definitely doesn't apply to that bike. So, why would it apply to any other bike? What exactly happens? Does the fuel pump lose its prime? I think not. Does all the dirt in the bottom of the tank get pumped into the fuel lines and clog the works? I doubt that.

Those were the reasons given in past decades for not running a FI automobile dry. I am pretty sure they do not apply any longer.

(02-05-2018, 01:26 PM)EmptySea_imp Wrote: Seems like an awful lot of consternation about the capacity. Ride it until the fuel warning light goes on...then ride it some more...then ride it somewhere close to a gas station....then ride it a little bit more...until you're REALLY nervous about running out...then ride it into the station and fill it up. If it takes more than 14.6L, then the tank probably holds 16.8L. If it takes less than 14.6L, then at some later ride, do the same steps, but ride a few miles more, keeping in mind the total miles you recorded from ride #1 as a guide. You'll figure out the fuel capacity AND the tank mileage this way.

Of course, you can also, just run it dry during ride #1 and avoid ride #2 entirely, but then you'd be depriving yourself of an opportunity to ride.

(02-05-2018, 02:00 PM)LongRanger_imp Wrote: Doc, I ran my '78 CB750F dry while crossing Utah back in 1979. I was fighting a stiff crosswind and was heeled over for many miles. Unbeknownst to me, because the bike was leaned over so far, it was able to suck the last of the fuel through the normal petcock tube. When the engine began to sputter, I flipped over to reserve, only to find there was precious little fuel remaining. The bike ran out of gas and rolled to a stop about ten miles later. The next town was 24 miles ahead. I wasted about three hours hitchhiking up and back to get gas.

To your point about crossing Nevada, Tonopah to Ely is about 170 miles and it's very difficult to do it at less than 90-100 mph. There is no gas (or anything else) between those towns. Gotta pay attention to your gas gauge at those speeds!

(02-05-2018, 01:26 PM)SportsterDoc_imp Wrote:

(02-05-2018, 12:14 PM)Ulvetanna_imp Wrote:

(02-05-2018, 10:58 AM)SportsterDoc_imp Wrote:

(02-05-2018, 05:58 AM)Nortoon_imp Wrote: Honda Canada has just posted the specs for the 2018 CB1100 RS.
They state the fuel tank holds 16.8 liters.

I doubt Honda has made a different tank just for the Canadian 2017 CB1100 EX.
So I am going to assume the tank on my 2017 CB1100 EX holds 16.8 liters .... until I run out of gas on some lonely back road.

The real question is not what the tank will hold, filled up from dry, but what is usable capacity, before the fuel pump intake sucks air.

A carbed bke could be run dry.

Not so with EFI.

Be good to figure that the last 1/2 gallon or 2 liters may not be usable.

Fortunately the pickup tube is towards the rear of the tank, so there is more usable going uphill, versus downhill.

The real question is not what the tank will hold, filled up from dry, but what is usable capacity, before the fuel pump intake sucks air.

A carbed bke could be run dry.

Not so with EFI.

Be good to figure that the last 1/2 gallon or 2 liters may not be usable.

Fortunately the pickup tube is towards the rear of the tank, so there is more usable going uphill, versus downhill. I ran my 2015 ZX-10R dry and had to push it to a gas station.

Fired instantly after I gassed up.

So I believe the notion that a fuel-injected engine cannot/should not be run dry is, or has, become archaic. It definitely doesn't apply to that bike. So, why would it apply to any other bike? What exactly happens? Does the fuel pump lose its prime? I think not. Does all the dirt in the bottom of the tank get pumped into the fuel lines and clog the works? I doubt that.

Those were the reasons given in past decades for not running a FI automobile dry. I am pretty sure they do not apply any longer.

Dry or to the point that the pump would not function?
A carbed bike can run a tank dry...may need some sloshing around.

A fuel pump cannot suck the last drop out. Once it sucks air, it is done, it has "lost its prime" until refueled. Most pickup tubes are a bit above the tank bottom.

Is it good to run a pump dry? Might get a bit warm, but I did that routinely on a 1996 Ford F150 with dual tanks, commuting weekly from Flagstaff, AZ to Ventura County, CA for about 4 months.

Sold the truck to the manager of our controls department. He still has it and no fuel pump issues reported.

The point was simply that a pump has some limitations over gravity flow.

A pump is less likely to pickup any bottom of tank sediment. If it can pick up sediment, it will do so at anytime, regardless of fuel level.

(02-05-2018, 01:26 PM)EmptySea_imp Wrote: Seems like an awful lot of consternation about the capacity. Ride it until the fuel warning light goes on...then ride it some more...then ride it somewhere close to a gas station....then ride it a little bit more...until you're REALLY nervous about running out...then ride it into the station and fill it up. If it takes more than 14.6L, then the tank probably holds 16.8L. If it takes less than 14.6L, then at some later ride, do the same steps, but ride a few miles more, keeping in mind the total miles you recorded from ride #1 as a guide. You'll figure out the fuel capacity AND the tank mileage this way.

Of course, you can also, just run it dry during ride #1 and avoid ride #2 entirely, but then you'd be depriving yourself of an opportunity to ride.

Well, I had the same questions in November.
I have gone past the far left segment of the fuel gauge flashing.
Don't remember for sure, but think it took 3.6 gallons (3.9 tank).

But, I did that in town.
In Nevada, away from Lost Wages, there are some trips with 154 miles between fueling opportunities. Places where signs read "open range 100 miles"

So, to plan for a trip, it helps to do the math. If I get as low as 45 MPG, if 3.9 is fully usable (I am skeptical), then I could go 175 miles. No uphill, no headwind, 65 MPH or less, probably 54 MPG x 3.9 gallons = 210 miles...but I certainly would not want to count on that.

West on the Extraterrestrial Highway has many passes at 6,000+ feet, generally significant altitude gain, long stretches suitable to push the speed (less MPG), before reaching the ghost town of Warm Springs (no services)...so it is a matter of how much extra fuel should I carry...perhaps 2 quart cans of TruFuel?

Generally, I figure 46 MPG as my worst, so 2 quarts = 23 miles.
Pushing a 540 pound bike may be good exercise, but pushing along a two lane with no shoulder and a rocky drop off is not my idea of relaxing!

(02-05-2018, 02:00 PM)LongRanger_imp Wrote: Doc, I ran my '78 CB750F dry while crossing Utah back in 1979. I was fighting a stiff crosswind and was heeled over for many miles. Unbeknownst to me, because the bike was leaned over so far, it was able to suck the last of the fuel through the normal petcock tube. When the engine began to sputter, I flipped over to reserve, only to find there was precious little fuel remaining. The bike ran out of gas and rolled to a stop about ten miles later. The next town was 24 miles ahead. I wasted about three hours hitchhiking up and back to get gas.

To your point about crossing Nevada, Tonopah to Ely is about 170 miles and it's very difficult to do it at less than 90-100 mph. There is no gas (or anything else) between those towns. Gotta pay attention to your gas gauge at those speeds!

(02-05-2018, 02:09 PM)EmptySea_imp Wrote: I didn't mean to imply that it is not important to know the capacity, Doc, and your trip plans are a great example of why it is important. I just was trying to point out that it just takes one ride to get the tank to (or extremely close to) empty and once it is filled up you will know the tank capacity. If you ran it until the pump started sucking air, you would know that capacity, too. Since there appears to be at least two different capacities listed by Honda, I think that the easiest way to verify it is first hand...and not on the side of mountain. LOL

(02-05-2018, 02:50 PM)Ulvetanna_imp Wrote:

(02-05-2018, 01:26 PM)SportsterDoc_imp Wrote:

(02-05-2018, 12:14 PM)Ulvetanna_imp Wrote:

(02-05-2018, 10:58 AM)SportsterDoc_imp Wrote:

(02-05-2018, 05:58 AM)Nortoon_imp Wrote: Honda Canada has just posted the specs for the 2018 CB1100 RS.
They state the fuel tank holds 16.8 liters.

I doubt Honda has made a different tank just for the Canadian 2017 CB1100 EX.
So I am going to assume the tank on my 2017 CB1100 EX holds 16.8 liters .... until I run out of gas on some lonely back road.

The real question is not what the tank will hold, filled up from dry, but what is usable capacity, before the fuel pump intake sucks air.

A carbed bke could be run dry.

Not so with EFI.

Be good to figure that the last 1/2 gallon or 2 liters may not be usable.

Fortunately the pickup tube is towards the rear of the tank, so there is more usable going uphill, versus downhill.

The real question is not what the tank will hold, filled up from dry, but what is usable capacity, before the fuel pump intake sucks air.

A carbed bke could be run dry.

Not so with EFI.

Be good to figure that the last 1/2 gallon or 2 liters may not be usable.

Fortunately the pickup tube is towards the rear of the tank, so there is more usable going uphill, versus downhill. I ran my 2015 ZX-10R dry and had to push it to a gas station.

Fired instantly after I gassed up.

So I believe the notion that a fuel-injected engine cannot/should not be run dry is, or has, become archaic. It definitely doesn't apply to that bike. So, why would it apply to any other bike? What exactly happens? Does the fuel pump lose its prime? I think not. Does all the dirt in the bottom of the tank get pumped into the fuel lines and clog the works? I doubt that.

Those were the reasons given in past decades for not running a FI automobile dry. I am pretty sure they do not apply any longer.

Dry or to the point that the pump would not function?
A carbed bike can run a tank dry...may need some sloshing around.

A fuel pump cannot suck the last drop out. Once it sucks air, it is done, it has "lost its prime" until refueled. Most pickup tubes are a bit above the tank bottom.

Is it good to run a pump dry? Might get a bit warm, but I did that routinely on a 1996 Ford F150 with dual tanks, commuting weekly from Flagstaff, AZ to Ventura County, CA for about 4 months.

Sold the truck to the manager of our controls department. He still has it and no fuel pump issues reported.

The point was simply that a pump has some limitations over gravity flow.

A pump is less likely to pickup any bottom of tank sediment. If it can pick up sediment, it will do so at anytime, regardless of fuel level.

(02-05-2018, 01:26 PM)EmptySea_imp Wrote: Seems like an awful lot of consternation about the capacity. Ride it until the fuel warning light goes on...then ride it some more...then ride it somewhere close to a gas station....then ride it a little bit more...until you're REALLY nervous about running out...then ride it into the station and fill it up. If it takes more than 14.6L, then the tank probably holds 16.8L. If it takes less than 14.6L, then at some later ride, do the same steps, but ride a few miles more, keeping in mind the total miles you recorded from ride #1 as a guide. You'll figure out the fuel capacity AND the tank mileage this way.

Of course, you can also, just run it dry during ride #1 and avoid ride #2 entirely, but then you'd be depriving yourself of an opportunity to ride.

Well, I had the same questions in November.
I have gone past the far left segment of the fuel gauge flashing.
Don't remember for sure, but think it took 3.6 gallons (3.9 tank).

But, I did that in town.
In Nevada, away from Lost Wages, there are some trips with 154 miles between fueling opportunities. Places where signs read "open range 100 miles"

So, to plan for a trip, it helps to do the math. If I get as low as 45 MPG, if 3.9 is fully usable (I am skeptical), then I could go 175 miles. No uphill, no headwind, 65 MPH or less, probably 54 MPG x 3.9 gallons = 210 miles...but I certainly would not want to count on that.

West on the Extraterrestrial Highway has many passes at 6,000+ feet, generally significant altitude gain, long stretches suitable to push the speed (less MPG), before reaching the ghost town of Warm Springs (no services)...so it is a matter of how much extra fuel should I carry...perhaps 2 quart cans of TruFuel?

Generally, I figure 46 MPG as my worst, so 2 quarts = 23 miles.
Pushing a 540 pound bike may be good exercise, but pushing along a two lane with no shoulder and a rocky drop off is not my idea of relaxing!

The bike stopped running. It would not restart. So the tank was empty. I pushed it to a gas station, filled the tank. It started. So the pump was sucking air (fumes) but there was not any problem restarting the bike once the tank was refueled.

The thing is, I heard all those tales of not wanting to ever run a fuel-injected car out of gas because it would have to be towed to the shop and serviced before it could be restarted, for one reason or another. So I just put a small amount of credence in them, never putting it to the test.

When my Ninja ran out of fuel and quit, I was concerned it wouldn't start because of it being EFI, but no need. Fired instanter after refueling.

All the fuel tanks I ever took apart (a metric boatload) had a fuel pickup and strainer somewhat higher than the outright bottom of the tank, but if one used fuel to or below that level, that was it. The "reserve" position picks up fuel below the main tube for a carbureted motorcycle, thus providing the "reserve" portion of the available fuel.

With a tank that had either side below the frame center tube, sometimes it would be possible (especially with a dirtbike) to simply lay the bike on its left side to get another pint or more of fuel. Or sometimes a crossover tube was fitted as on my 1989 R100GS.

But I think today, there is no concern about running an EFI motorcycle out of fuel for any reason. I know I've done it with no problems. I would like to hear from anyone who ran out of gas with an EFI bike and did have a problem restarting it.

As far as running out of gas, some CA bikes have about a quart less fuel tank capacity, some don't. The ZX-10R has two different tanks listed, one for the CA bike and another for the 49-state version. I did my fuel calculations based on the stated capacity for the 49-state since I hadn't read of what the difference really was. I found out. After that I was very careful never to get close to the fuel limits on my CB1100, which had a small tank to begin with. Never did run out.

(02-05-2018, 03:04 PM)Guth_imp Wrote: People used to say that it wasn't wise to run a fuel tank down to empty because of the sediment that might have formed and settled in the bottom of the tank over many years time. There probably aren't any CB1100s that yet qualify for such concerns.

(02-05-2018, 03:04 PM)Guth_imp Wrote: People used to say that it wasn't wise to run a fuel tank down to empty because of the sediment that might have formed and settled in the bottom of the tank over many years time. There probably aren't any CB1100s that yet qualify for such concerns.

(02-05-2018, 02:50 PM)SportsterDoc_imp Wrote:

(02-05-2018, 02:00 PM)LongRanger_imp Wrote: Doc, I ran my '78 CB750F dry while crossing Utah back in 1979. I was fighting a stiff crosswind and was heeled over for many miles. Unbeknownst to me, because the bike was leaned over so far, it was able to suck the last of the fuel through the normal petcock tube. When the engine began to sputter, I flipped over to reserve, only to find there was precious little fuel remaining. The bike ran out of gas and rolled to a stop about ten miles later. The next town was 24 miles ahead. I wasted about three hours hitchhiking up and back to get gas.

To your point about crossing Nevada, Tonopah to Ely is about 170 miles and it's very difficult to do it at less than 90-100 mph. There is no gas (or anything else) between those towns. Gotta pay attention to your gas gauge at those speeds!

That must have been a serious cross-wind!!!

Working on Ipad, I thought I dropped this post, which is now redundant.

Tried to delete, but do not have permission